Sash balance



'Feb- 1941. A. J. ROEQENTRETER ,2 ,76

SASH BALANCE Filed July 15, 1940 11 INVENTOR.

Patented Feb. 4, 1 941 UNITED STATES} PATENT OFFICE 2,230,763 sasnBALANCE Application July 15, 1940, Serial No. 345,489

6 Claims.

This invention relates to a sash balance, with particular reference tothe style of construction that employs a spring tension element, and hasfor its object to provide a simple and practical arrangement that can bemanufactured and installed at a minimum cost, and the parts of which areconcealed from view when in place on a window sash and frame.

More particularly, the invention is intended to afford a structureespecially adaptable to low priced houses because of its low cost, andwhich includes as its essential parts a rotatable member preferably inthe form of a spiral or twisted bar and a coil spring wound around thebar and retained in its convolutions, the spring bee ing under tensionas a window is raised or lowered from its initial position and therebyacting to hold the bar, and with it the window to which it is attached,in any adjusted position.

Another object of the invention is to afford a construction of few partswhich can be readily and quickly attached to a sash and frame andassembled in proper operative relation thereto.

One objection to spring sash balances as heretofore manufactured hasbeen'the necessity of having to wind or tension the spring element atthe time the device is applied to a sash, making an inconvenient anduncertain operation, and it is another object of the invention toprovide a construction of such a character that the spring can be woundat the factory and maintained underpredetermined tension untilinstalled, thus making it unnecessary to wind the spring at the time ofattaching the device .and insuring an efficient and standardized springtension determinable at the factory.

",Io these and other ends, the invention consists'in the constructionand arrangement of parts that will appear clearly from the followingdescription when read in conjunction with the accompanying drawing, thenovel'features being pointed out in the claims following thespecification.

In the drawing:

Fig. l is a view in front elevation, partially in section, illustratinga preferred embodiment of the invention as applied to a window sash andframe;

Fig. 2 is a view inside elevation of the upper part of the sash balance;

Fig. 3 is a plan view of the same;

Fig. 4 is a bottom plan view, and

Fig. 5 is a sectional view on the line 5-5 of Fig. 1.

Referring more particularly to the drawing in which like referencenumerals refer to the same parts throughout the several views, Idesignates a window sash slidable within the frame 2 and mortised at itsedges to receive the mechanism to be described. The structure includessupport- I! ing means in the form of a plate 3 that is rigidly securedto the upper end of the sash with its outer portion overlying themortised portion in the side of the sash, and above said mortise, theplate 3 is recessed to afford an'opening or pocket 10 4 formed bydepending walls 5 and lateral flanges 6 separated by a slot 1, andadapted to receive and support the controlling spring and rotatable orspiral member that will now be described in detail.

The rotatable member preferably consists of a twisted or. spiral bar 8which is rotatably mounted in relation to the supporting means alreadydescribed, and so associated with the coil spring 9 as to place the sameunder tension when the, 20 spiral bar is moved endwise upon movement ofthe sash. Preferably this relationship is effected by mounting thespiral bar 8 upon the coil spring 9, as shown, by providing aright-angled or lateral portion or lug ill .at the upper end of the 25spiral bar, said lug Ill being provided with an opening through whichspring 9 extends, the spring thus affording a bearing for the rotatablespiral bar. Beneath the lug Ill, the coil spring 9 is twisted around thespiral bar convolutions thereof, and at the lower end of the bar, thecoil spring 9 is connected thereto by being attached between a pair ofears II, or otherwise fixedly secured in any suitable fashion to thebar.

The coil spring 9 is fixedly secured at its upper end to 'the supportingmeans in any suitable manner, as for instance, by having its upper endextending through a recess in and rigidly connected to a squared plateor head l2 which 40 is located in the recess 4 resting upon the flanges6 and held against rotation in said pocket. The squared plate or head [2which is fixedly connected to the upper end of the spring is of suchsize as to strike the side walls of the recess 4 45 and is thus heldagainst rotation, after being assembled in position by sliding the coilspring 9 laterally through slot 1. I3 is a washer or bearing platesurrounding thespring 9 and located between the lower surfaces of theflanges 6 and 50 the adjacent surface of the lug ill on the spiral bar.The spring 9 carrying the spiral bar can be inserted through the slot 1in the plate 3 into position on the supporting flanges 6, and theendwise tension of the spring Ill, being connected 55 8 following the 30fixedly to the lower end of the spiral'bar, holds the latter up againstthe supporting means with sufiicient tightness to prevent accidentaldisplacement of the parts. i

' The spiral bar is adapted to be rotated in any suitable fashion whenthe sash is rnoved, and this may be accomplished conveniently by a plateH or other means, permanently attached to the window frame, and carryinglugs l5 that embrace the opposite edges of the spiral bar 8.

Thus as the window and the mechanism mounted thereon moves, the spiralbar 8 is rotated by the lugs IS on the stationary plate H. The spiralbar 8 being fixed at its lower end to the spring 9, which in turn isfixed at its opposite end to the supporting means, winds the spring orincreases the tension thereof as the window is moved in one direction,thus exerting a tendency on the spiral bar to rotate to its initialposition, and in this manner the bar is held in frictional engagementwith the lugs IS with sufficient force to retain the window in anyposition to which it is moved. Itwill be observed that since the upperend of the spring 9 is fixed to the supporting means and cannot turn,while its lower end is fixedly connected to the lower end of the spiralbar, when the bar is rotated about .the spring, it necessarily followsthat the spring is stretched around the bar and placed under increasingtension, depending upon the number of turns given the spiral bar, butthere is always sufiicient tension of the spring to hold the window atany given point in its vertical travel.

. It is desirable to have the controlling spring under a certain amountof initial tension, and in spring balances of previous design, it hasbeen necessary to wind the spring to the desired extent at the time ofits installation. This has been somewhat diificult and requires time andexperience by the operator, but with the present con- 'struction, it ispossible to tension or wind the spring relatively to the spiral bar andfix its predetermined tension at the factory, so that when the parts areinstalled, the operator has only to release the spring after themechanism is fixedly attached to the sash and housing.

This can be accomplished in various ways, as for instance by means of aU-shaped staple or key l6 that straddles the head I! and extends throughopenings in the flanges 6, extending downwardly to opposite sides of thelug Ill. The spiral bar 8 is turned or rotated relatively to the spring9 at the factory to place the spring under the desired tension,whereupon the key or looking member I6 is dropped through the holes inthe flanges 6 engaging on opposite sides of the lug l and acting toprevent turning of the latter. The parts are maintained in this positionuntil after the device is installed on a sash with the spiral bar 8 inengagement with the lugs i of the fixed plate It, after which theoperator removes the key or locking member I6 and the spiral bar 8 isthen free to turn when the window is raised or lowered, as the case maybe. I! designates a device secured to the sash and engaging the lowerend of the spring and spiral bar unit and acting as a bearing for thelower end of the spring to maintain the spring and spiral bar in properrelation and out of contact with the frame as the sash is moved.

While'the invention has been described with reference to the detailedembodiment herein shown, it is not confined to any particular structuraldetails, and this application is intended to cover any modifications ordepartures that may come within the novel'principles of the improvementor the scope of the following claims.

I claim:

1. A sash balance construction comprising supporting means, a spiralmember rotatably 5 mounted in relation to the supporting means, a coilspring which lies lengthwise along the spiral member bodily conformingto the convolutions thereof and having one end fixed to the supportingmeans and its opposite end fixed to said 10 spiral member, and anactuator positionable in relatively fixed relationship to the spiralmember for engagement therewith and acting to turn the spiral memberwhen relative endwise movement is eflected between the spiral member andactuator.

2. A sash balance construction comprising supporting means, a spiral barrotatably mounted in relation to the supporting means, a coil springwhich lies lengthwise along the spiral bar bodily conforming to theconvolutions thereof and having one end fixed to the supporting meansand its opposite end fixed to the adjacent end of said spiral bar, andan actuator positionable in relatively fixed relationship to the spiralbar for engagement therewith and acting to effect rotation thereof uponrelative endwise movement between the spiral bar and the actuator.

3. A sash balance construction comprising supporting means, a spiral barrotatably mounted in relation to the supporting means, a coil springwound around said spiral bar having one end fixed thereto and its otherend fixed to said supporting means, the end of the spiral bar adjacentto the supporting means being journalled and rotatable on said spring,and an actuator positionable in relatively fixed relationship to thespiral bar and engageable therewith to effect its rotation when relativeendwise movement is effected between the spiral bar and the actuator.

4. A sash balance construction comprising supporting means, a spiral barrotatably inounted in relation to the supporting means, a coil springwound around said spiral bar following the convolutions thereof, the endof the spiral bar adjacent to said supporting means having a laterallyextending portion journalled on said spring for rotation thereon whilethe opposite end of the spiral bar is fixedly connected to the adjacentend of the spring, and an actuator positionable in relatively fixedrelationship to the spiral bar and having operative engagement therewithto effect its rotation when relative endwise movement between the spiralbar and the actuator is efiected.

5. A sash balance construction comprising supporting means, a rotatablemember mounted to turn relatively to said supporting means, a coilspring which lies lengthwise along the rotatable member bodilyconforming to a spiral around the rotatable member, said coil springhaving one end fixedly connected to the rotatable member while itsopposite end is fixedly connected to said supporting means, and anactuator positionable in relatively fixed relation to said rotatablemember and operatively connected thereto for effecting its rotation whenrelative endwise movement between said rotatable member and the actuatoris effected.

6. A sash balance construction comprising supporting means including arecessed plate slotted at its edge, a coil spring extending through saidslot and fixedly carrying a head located in said recess, a spiral barhaving a laterally extending- 'the bar against said plate, and anactuator positionable in relatively fixed relationship to the spiral barand acting'to efiect rotation thereof when relative endwise movement iseffected between the spiral bar and the actuator.

ALBERT J. ROSEN'I'RETER.

